Even if you get a cheap Trailgear kit
Tacoma | Toyota, Suzuki Samurai, and Jeep Off Road Parts and do it yourself, one of the 2k$ kits will probably run you about 3-4k to do it right. If you want a locked Solid axle kit that will run you 4-5k. (keep in mind these are leaf spring kits that ride like crap and flex horribly compared to coil based swaps. Coil based swaps will run you a bit more.)
So lets say it cost you 4k to do your own leaf based SAS. The good quality axles we get from CVJ are about 200$ and then 50$ core fees (Im rounding for easy math)
so lets say they run you 150$ an axle which is actually a bit cheap.
you would have to break 26 axles to make that worth it. Thats if you did your own SAS. I think Glen has broken like 15? I think now? Sn0wrunner maybe 6? And thats over the past 2-3 wheeling seasons I think....
thats no where near the 26 axles it would take to get even close to the same amount of money it would cost to get a solid axle. Plus, part of the great thing about the 4runner is the nice ride it has. Now you may have a solid axle, but you dont have close to the ride you used to.
I've thought quite a bit about SAS over the past couple years, For me its hard to justify especially if Yoshida is successful with these new CVs at 500$ a piece. I like the ride my 4runner has and I can go pretty much everywhere I want to go already. And Im not locked yet either.